SCExAO Frame delivered!

Last week, the frame that will carry SCExAO when at the telescope was finally delivered to Subaru HQ! The big white painted welded steel structure that looks sturdy enough (thanks to Doi-san for the design!) now sits in the Subaru Simlab, ready to host the SCExAO bench, the HiCIAO camera, all of the necessary electronics and computers with spare room at the Subaru Telescope IR Nasmyth platform.

There is still a fair bit of work to be done on the frame: attachment holes to be drilled, pads for the frame resting on the floor and rails for lateral positioning of the instruments... but this is a big part of the project and having it finally delivered after over a year of discussion and design is quite a relief!

Good and bad news for SCExAO

No post in January... what's going on with the project? Let's start with some good news: in December, the SCExAO project was reviewed by a Subaru Telescope committee. Late January, the review report was sent to the Director who recommended to give SCExAO at least one night in the semester S10A, likely in May or June, before the telescope summer shutdown for re-coating of the primary mirror... yes!

The bad news is that only two days after this decision was announced, Subaru's AO system experienced a major problem, which permanently damaged the deformable mirror, making it unusable. The AO group at Subaru is working hard on trying to bring the AO back to life, however the replacement mirror won't be delivered before the end of October, which means that SCExAO is unlikely to go to the telescope before 2011.

While this is clearly a disappointment, we just have to make good use of this time. We have plenty of things to do: integrate and test the new frame for SCExAO and HiCIAO, which should be delivered toward the end of February (this month) is a major item on the list, write and polish the existing software for the control of SCExAO is another.

A hui hou!

Software for two Xenics cameras!

Yep, you've read right: we now have two of the Xenics IR cameras. The first we purchased will be dedicated to the low-order wavefront sensor, the second will have the privilege of being our "science" detector for the commissioning of SCExAO, before we try and add HiCIAO, and might even be able to do some science itself!

Today, we finally managed to control both cameras from the same computer... hurray! This server/client architecture we've developed is actually proving very handy: one server per camera, each one awaiting for connections (via the local network or directly from the SCExAO control computer) listening to their special port number.

The client can now ask either of the cameras (or both) to take images, query for or update the camera configuration (exposure time, subarray mode, gain), or tell it to shutdown. Now that these detectors are both working, we can turn off the visible laser diode: this new year will be bright in the infrared for SCExAO!

SCExAO will be at SPIE (part 2)

Just like the title of the post says: part 2 of our massive submission of abstracts for the the next astronomy SPIE conference.

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Olivier submitted:

The Subaru Coronagraphic Extreme AO (SCExAO) system: Wavefront control and detection of exoplanets with coherent light modulation in the focal plane

The SCExAO system is designed to enable high contrast imaging at small angular separation (less than 0.5”) in the near-IR. It receives light from Subaru Telescope’s AO system and includes a second step of wavefront control and a high performance PIAA coronagraph. Light is then sent to the HiCIAO camera. For wavefront sensing, SCExAO uses a MEMS type deformable mirror to introduce known diversity in the pupil phase. The corresponding modulation is detected in the science focal plane, and leads to a measurement of the residual wavefront aberrations. The same modulation is also simultaneously used to differentiate residual scattered starlight (which is coherent with the light introduced in the focal plane by the modulation) from actual sources (planets, disks).

This combined wavefront control and coherent detection scheme is ideally suited for detection of faint companions at small angular separation. Detailed numerical simulations and recent laboratory results show that this techniques can calibrate and remove static and slow speckles which traditionally limit high contrast detections. A visible light lab prototype system at Subaru Telescope recently demonstrated speckle halo reduction to 2e-7 contrast within 2 lambda/D, and removal of static coherent speckles to 3e-9 contrast.

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Frantz submitted:

The Subaru Coronagraphic Extreme AO system: progress report

In 2009 our group started the integration of the SCExAO project, a highly flexible, open platform for high contrast imaging at the highest angular resolution, to be inserted between the coronagraphic imaging camera HiCIAO and the 188-actuator AO system of Subaru. In its first version, SCExAO combines a MEMS-based wavefront control system feeding a high performance PIAA-based coronagraph, that suppresses the central obscuration and the thick spider vanes while preserving throughput and angular resolution. It also includes a coronagraphic low-order wavefront sensor, a non-redundant aperture mask and a visible imaging mode, all of them designed to take full advantage of the angular resolution (40 mas in the H-band) that an 8-meter telescope has to offer.

Group pictures for December 2009!

Today, Vincent is leaving Hawaii to France for his "X-mas break"... because when he gets back in January next year, others will have left for good, we took a couple group pictures. The first one was taken in the office and from left to right you have: Frederic Vogt, Kaito Yokochi, Vincent Garrel, Frantz Martinache, Olivier Guyon and Takashi Yoshikawa. The second one was taken in the Subaru Simlab, right in front our our SCExAO clean booth. From left to right you have: Frantz Martinache, Frederic Vogt, Olivier Guyon, Vincent Garrel (standing), Kaito Yokochi and Takashi Yoshikawa.

Happy holidays Vincent and see you next year!!

Optical design schematic

Kaito Yokochi just made this nice schematic of the lab configuration of the SCExAO coronagraph. It'd be a pity not to post it here... thanks Kaito!

Cover panels snug fit

The protection cage introduced in a previous post was just a prelude... now we have some pretty good looking slick black panels to protect the bench from dust, light and coffee spills to complete the cover... take a look (picture courtesy of Takashi):

You may notice the transparent panels on the right side of the picture: it happens fairly regularly that visitors show up in the lab and want to see what the experiment looks like. We figured that a sneaky double panel system (transparent underneath the black) would let people see the guts of SCExAO and still protect the bench from things like unsuspected screwdriver attacks.

Before we complete the enclosure (on the sides), we need to neaten all the serial and USB cables that connect to the motors, actuators and cameras mounted on the bench.